Constructing Computerized Adaptive Testing in Chemistry : Acid – Base for Matthayomsueksa 5 Students

Abstract

The purpose of this research was to construct the Computer Adaptive Testing (CAT)
and investigate the quality of CAT in Chemistry : Acid–Base for Matthayomsueksa 5 Students
(grade 11). The sample was 2,180 primary students in the Mahasarakham province for the
academic year 2013 ; which were obtained using the Multi – stage Random sampling
technique. They were assigned to 3 groups : group 1 consists of 300 students who were
used for testing to find out each item quality based on the classical test theory (CTT), group
2 consists of 1,800 students who were used for testing to find out each item quality based
on the item response theory (IRT) and group 3 consists of 80 students who were used for
testing to find out quality of the computerized adaptive tests. The results of the study were
as follows :
1. The following were the result to the construct Computer Adaptive Test
(CAT) in Chemistry : Acid – Base
1.1 The item characteristic according to the classical test theory (CTT) using 6,
65 - item tests. It was found that 300 test items met the requirements were as follows :
the difficulties (p) was valued at .20 to .80 and the discriminating powers (r) was valued at
.25 to .85.
1.2 The item characteristic according to the item respond theory (IRT) using 6,
50 - item tests. It was found that 222 test items met the requirements were as follows : the
a – parameter was valued at .390 to 2.339 , the b – parameter was valued at -2.415
to 2.400 and the c – parameter was valued at .097 ถึง .298
1.3 The CAT is compatible with Window 7 or Window 8. After a student
has finished doing the test. It was reported the ability of the student was one of these :
excellent , good , moderate , fair and poor.
1.4 Base on the CAT on 5 professional of media computer. The average of
the total finding was valued at 4.15 and the Standard Deviation was valued at .58
2. The following were the result to the analyzing the quality of adaptive
testing in Chemistry : Acid – Base
2.1 For the reliability by trying out the constructed tests with 80 students in
Group 2. They were tested twice, 2 weeks after Testing 1. The test-takers ability scores from
the CAT in the 2 testings were calculated to find out correlation coefficient which was the
test reliability. The reliability obtained was .851.
2.2 For the criterion-related validity by an ability mean score from the 2
testings from the CAT and score of chemistry were calculated to find out correlation
coefficient which was criterion-related validity, it was found that the criterion-related validity
was .884.